Field of the Invention
The present invention relates to a clutch burst prevention method, and more particularly to a clutch burst prevention method for a vehicle with a double clutch transmission (DCT) which can prevent a clutch from bursting when a stuck phenomenon occurs on a low gear of a non-drive input shaft.
Description of Related Art
A double clutch pack of a DCT is an assembly of various parts. When rotating at a high speed (10000 revolutions per minute (RPM) or more), these parts may be disassembled or damaged by centrifugal force and, simultaneously, noise and shock may be generated. As such, if damage to the clutch, e.g., burst, is caused, the power transmission function of the clutch is lost, thus creating danger to occupants of the vehicle. Therefore, there is the need for preventing a clutch burst phenomenon from being caused under any driving conditions.
When the clutch is directly connected to an engine, in other words, it is in a state related to a drive input shaft. the RPM of the drive input shaft depends on the RPM of the engine. However, when the clutch is in a state related to a non-drive input shaft, the RPM thereof varies depending on the driving speed of the vehicle and an engaged gear stage.
When a low shift gear is pre-engaged with the non-drive input shaft while the vehicle moves at high speed, the RPM of the clutch is abnormally increased, whereby a clutch burst phenomenon may be caused. An image of a clutch damaged by such a clutch burst phenomenon is shown in FIG. 1.
Particularly, if a low gear of the non-drive input shaft is engaged when the vehicle moves at high speed and a failure of a gear actuator in which the low gear is not disengaged is caused, the probability of occurrence of the clutch burst phenomenon is increased. Such a failure is illustrated in FIG. 2. Referring to FIG. 2, a drive input shaft is coupled to an engine, and drive force is transmitted to wheels through a sixth gear. If under normal circumstances, a non-drive shaft should be coupled to a fifth or seventh gear to prepare shifting gears. However, due to occurrence of a failure, the non-drive shaft is in a state in which it is coupled to a first gear.
Consequently, the RPM of the wheels that are rotated at high speed is amplified by the first gear, whereby the first clutch, that is, the clutch that is mounted to the non-drive rotating shaft, is rotated at abnormally high speed. Therefore, a control method of limiting the RPM of the non-drive rotating shaft to a predetermined level or less when the above-mentioned problem occurs is required.
In a conventional DCT clutch control method according to the related art, it was determined that, if the RPM of an input shaft is an RPM at which clutch burst occurs or more when synchronization starts by means of a shifting operation, the transmission malfunctions. In this way, failure is diagnosed in early stage, whereby additional damage can be prevented.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.